Configuring the TCP proxy

NOTE: You must have a valid software maintenance contract to use the TCP Proxy.

It is possible that for cloud-based systems, e.g. Microsoft Azure, port 25 is blocked by the provider. However, port 25 is required for sending emails, and port 25 being blocked prevents NoSpamProxy from operating on such a system.

We offer a solution in the form of our TCP proxy. This system can be activated in NoSpamProxy as described below. Each outbound connection is routed to a routable IPv4 address on the TCP level through the TCP proxy for NoSpamProxy. The emails will be sent from the server via port 443 to the TCP proxy and from there via port 25 to the recipient system.

NOTE: Before you activate the TCP proxy via PowerShell, you must remove the old TCP proxy to be activated via the configuration file (if you have used it). See Removing the "old" TCP proxy.

  1. Place the Root CA certificate in the Microsoft certificate store in the computer account under Trusted Root Certification Authorities > Certificates on the server with the Gateway Role.
  2. Enter the following commands in PowerShell
    :Connect-Nsp -IgnoreServerCertificateErrorsSet-NspOutboundSendConnector
    -Smtp -TcpProxyMode UseCustom -TcpProxyHost "proxy.nospamproxy.com" -TcpProxyPort 443 -Name "Default connector for outbound emails"

    NOTE: The TcpProxyMode parameter is available for version 15.5. and higher

  3. In the NoSpamProxy Command Center under Configuration > NoSpamProxy components > Gateway Roles edit the appropriate Gateway Role and change the value for SMTP Server Name to the value outboundproxy.nospamproxy.com.

Removing the "old" TCP proxy

To remove the old TCP proxy to be activated via the configuration file, proceed as follows:

  1. Stop the Gateway Role via the NoSpamProxy console or the Windows services
  2. Open a text editor using administrative rights on the system where the Gateway Role is installed.
  3. Open the configuration file "Gateway Role.config" from the directory C:\ProgramData\Net at Work Mail Gateway\Configuration.
  4. Search the file for <smtpServicePointConfiguration.
  5. Delete the following attribute:
    isProxyTunnelEnabled="true" proxyTunnelAddress="proxy.nospamproxy.com"
  6. Save the file and close the editor.
  7. Start the Gateway Role.